Year	Percent
1999-01-01	2.18802487876719
2000-01-01	1.98120292936732
2001-01-01	1.73749818766667
2002-01-01	1.91888031350912
2003-01-01	2.01606919148327
2004-01-01	2.20771783720404
2005-01-01	2.73665136264446
2006-01-01	2.90961735138971
2007-01-01	2.83309284476557
2008-01-01	2.97132605966266
2009-01-01	3.60123475513080
2010-01-01	4.05401415990538
2011-01-01	4.14852631225997
2012-01-01	4.13026692911419
2013-01-01	4.00250761536000